Thin film transistor and method for manufacturing a display panel

ABSTRACT

Embodiments of the present invention relate to a thin film transistor and a manufacturing method of a display panel, and include forming a gate line including a gate electrode on a substrate, forming a gate insulating layer on the gate electrode, forming an intrinsic semiconductor on the gate insulating layer, forming an extrinsic semiconductor on the intrinsic semiconductor, forming a data line including a source electrode and a drain electrode on the extrinsic semiconductor, and plasma-treating a portion of the extrinsic semiconductor between the source electrode and the drain electrode to form a protection member and ohmic contacts on respective sides of the protection member. Accordingly, the process for etching the extrinsic semiconductor and forming an inorganic insulating layer for protecting the intrinsic semiconductor may be omitted such that the manufacturing process of the display panel may be simplified, manufacturing cost may be reduced, and productivity may be improved.

CROSS-REFERENCE TO RELATED APPLICATION

This is a divisional of U.S. patent application Ser. No. 12/331,361,filed Dec. 9, 2008, which application claims priority to and the benefitof Korean Patent Application No. 10-2007-0128464 filed in the KoreanIntellectual Property Office on Dec. 11, 2007, the entire contents ofwhich are incorporated herein by their references.

BACKGROUND

(a) Technical Field

Embodiments of the present invention generally relate to a thin filmtransistor and a manufacturing method of a display panel.

(b) Related Art

A liquid crystal display (LCD), a plasma display panel (PDP), and anorganic light emitting device (OLED) are among widely used flat paneldisplays.

The LCD is a display device using electro-optical characteristics ofliquid crystals in which light transmission amounts are varied accordingto the intensity of an applied electric field to thereby realize thedisplay of images. The PDP is a display device for displaying images byusing plasma generated by gas discharge. In the OLED, electrons andholes are injected into an organic illumination layer, respectively,from a cathode (the electron injection electrode) and an anode (the holeinjection electrode). The injected electrons and holes are combined togenerate excitons, which illuminate when converting from an excitedstate to a ground state.

In addition, as a display device that is widely used, a field emissiondisplay (FED) utilizing the tunneling effect of quantum mechanics toemit electrons from electron emission sources formed on cathodeelectrodes may be provided. The emitted electrons strike a phosphorlayer formed on an anode electrode to illuminate the phosphor layer andthereby result in the display of images. An electrophoretic display(EPD) is a display device utilizing the electrophoretic phenomenon torepeatedly write or erase information made of symbols such as charactersand numbers.

Among the flat panel displays, an active matrix type in which each pixelis independently controlled by including switching elements such as athin film transistor is generally used. The thin film transistor may beclassified as a top gate type and a bottom gate type according to theposition of a gate electrode. Amorphous silicon and polysilicon aregenerally used as a material of a semiconductor forming a channel of thethin film transistor, wherein the amorphous silicon is widely used inthe bottom gate type and the polysilicon is widely used in the top gatetype.

In the bottom gate type, a gate electrode is disposed under asemiconductor member, and a source electrode and a drain electrodecontact respective sides of the semiconductor member. The channel of thethin film transistor is formed in the portion that is disposed betweenthe source electrode and the drain electrode in the semiconductor and iscovered by an insulating layer.

When the channel of the thin film transistor, which is made of thesemiconductor layer, is formed without a protection layer, theelectrical characteristics of the thin film transistor are deterioratedby moisture or impurities incorporated from an atmosphere.

Particularly, in a COA (color filter on array) structure in which acolor filter is formed on the same substrate as the thin filmtransistor, the organic layer of the color filter directly contacts thechannel layer such that the channel layer is contaminated, andoutgassing is generated from the organic layer of the color filterthrough a heat treatment of a following process such that a problem suchas an image sticking is generated. Accordingly, an insulating layer isformed to prevent these problems, but the manufacturing process iscomplicated.

SUMMARY

One or more exemplary embodiments of the present invention simplify amanufacturing process of a thin film transistor and a display panel byomitting an etching step for an ohmic contact member and a process foradditionally forming an insulating layer for protecting the channellayer.

A manufacturing method of a display panel according to an exemplaryembodiment of the present invention includes forming a gate lineincluding a gate electrode on a substrate, forming a gate insulatinglayer on the gate electrode, forming an intrinsic semiconductor on thegate insulating layer, forming an extrinsic semiconductor on theintrinsic semiconductor, forming a data line including a sourceelectrode and a drain electrode on the extrinsic semiconductor, andplasma-treating a portion of the extrinsic semiconductor between thesource electrode and the drain electrode to form a protection member andohmic contacts divided on both sides of the protection member.

The manufacturing method may further include forming an organic layer onthe protection member. The organic layer may contact the protectionmember.

The manufacturing method may further include forming a pixel electrodeconnected to the drain electrode on the organic layer.

The intrinsic semiconductor may comprise polysilicon and the extrinsicsemiconductor may comprise polysilicon.

The forming of the extrinsic semiconductor may comprise plasma-treatmentof the surface of the intrinsic semiconductor under phosphine.

The manufacturing method may further comprise cleaning the intrinsicsemiconductor after forming the intrinsic semiconductor before formingthe extrinsic conductor.

The cleaning of the intrinsic semiconductor may use hydrogen fluoride.

The thickness of the extrinsic semiconductor may be in a range fromabout 10 Å to about 100 Å.

The protecting member may comprise a portion of the same conductiveimpurity as the ohmic contacts.

A manufacturing method of a display panel according to another exemplaryembodiment of the present invention includes forming a gate electrode ona substrate; forming a gate insulating layer on the gate electrode;sequentially depositing a first material layer, a second material layer,and a third material layer on the gate insulating layer; etching thethird material layer, the second material layer, and the first materiallayer to form a data conductor, an extrinsic semiconductor, and anintrinsic semiconductor; etching the data conductor to form a sourceelectrode and a drain electrode and simultaneously exposing a firstportion of the extrinsic semiconductor; plasma-treating the firstportion of the extrinsic semiconductor to form a protection member andto simultaneously form ohmic contacts divided on both sides with therespective protection member; forming a color filter on the sourceelectrode, the drain electrode, and the protection member; and forming apixel electrode connected to the drain electrode on the color filter.

The manufacturing method may further include forming a capping layer ofan inorganic insulator on the color filter.

The plasma treatment may be executed by using a plasma generationapparatus including oxygen injected into a chamber. Argon (Ar) gas orhelium (He) may be additionally injected into the chamber.

The sequential etching of the third material layer, the second materiallayer, and the first material layer, the etching of the data conductor,and the plasma treatment of the extrinsic semiconductor may besequentially executed in the same plasma generation apparatus.

The forming of the source electrode and the drain electrode may includeforming a photosensitive member on the third material layer, andremoving the exposed portion of the data conductor by using thephotosensitive member as a mask. The plasma-treating of the firstportion of the extrinsic semiconductor may be executed under a conditionin which the photosensitive member remains on the source electrode andthe drain electrode.

A thin film transistor according to an exemplary embodiment of thepresent invention includes a gate electrode, a semiconductor on the gateelectrode, a source electrode on the semiconductor, a drain electrodedisposed at a distance from the source electrode, ohmic contactsincluding a first portion disposed between the semiconductor and thesource electrode and a second portion disposed between the semiconductorand the drain electrode, a protection member connected between the firstportion and the second portion of the ohmic contacts, the protectionmember comprising a portion of same conductive impurity as the ohmiccontacts.

The protection member may comprise an insulator. The insulator may be asilicon oxide. The protecting member may be corresponding to the gateelectrode. The protection member may be expanded in a depth direction tothe gate electrode consuming a portion of the top surface of thesemiconductor. The protection member may comprise an upper portion withthe impurity and a lower portion without impurity.

The display device may further include a color filter formed on theprotection member and contacting the protection member.

The display device may further include a capping layer formed on thecolor filter.

A sum planar shape of the ohmic contacts and the protection member maybe substantially the same as a planar shape of the semiconductor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a layout view of a display panel according to an exemplaryembodiment of the present invention;

FIG. 2 is a cross-sectional view of the display device shown in FIG. 1taken along the line II-II;

FIG. 3 to FIG. 8 are cross-sectional views sequentially showing amanufacturing process of the display panel according to one or moreembodiments;

FIG. 9 is a layout view of a display device according to anotherexemplary embodiment of the present invention;

FIG. 10 is a layout view of the thin film transistor array panel shownin FIG. 9;

FIG. 11 is a layout view of the common electrode panel shown in FIG. 9;

FIG. 12 is a cross-sectional view of the display device shown in FIG. 9taken along the line XII-XII;

FIG. 13 is a cross-sectional view of the display device shown in FIG. 9taken along the line XIII-XIII; and

FIG. 14 and FIG. 15 are graphs of the results of the operations of thethin film transistors according to one or more embodiments.

FIG. 16 and FIG. 17 are Time of Flight Secondary Ion Mass Spectrometry(TOF-SIMS) graphs according to one or more embodiments.

DETAILED DESCRIPTION

Embodiments of the present invention will be described more fullyhereinafter with reference to the accompanying drawings, in whichexemplary embodiments of the invention are shown. As those skilled inthe art would realize, the described embodiments may be modified invarious different ways, all without departing from the spirit or scopeof the present disclosure.

In the drawings, the thickness of layers, films, panels, regions, etc.,are exaggerated for clarity. Like reference numerals designate likeelements throughout the specification. It will be understood that whenan element such as a layer, film, region, or substrate is referred to asbeing “on” another element, it can be directly on the other element, orintervening elements may also be present. In contrast, when an elementis referred to as being “directly on” another element, there are nointervening elements present.

Now, a display panel according to an exemplary embodiment of the presentinvention will be described in detail with reference to FIG. 1 and FIG.2.

FIG. 1 is a layout view of a display panel according to an exemplaryembodiment of the present invention, and FIG. 2 is a cross-sectionalview of the display device shown in FIG. 1 taken along the line II-II.

Referring to FIG. 1 and FIG. 2, a gate line 121, a gate insulating layer140, a semiconductor 154, ohmic contacts 163 and 165 and a protectionmember 167, a data line 171, and a drain electrode 175 are sequentiallyformed on a substrate 110 comprising an insulating material such asglass or plastic.

The gate line 121 transmits gate signals and includes a gate electrode124, and the data line 171 transmits data signals and includes a sourceelectrode 173 extending toward the gate electrode 124. The drainelectrode 175 is separated from the data line 171, and is opposite tothe source electrode 173 with respect to the gate electrode 124.

The semiconductor 154 may comprise a material such as hydrogenatedamorphous silicon or polysilicon, the ohmic contacts 163 and 165 maycomprise amorphous silicon doped with an impurity at a highconcentration, or polysilicon with an impurity at a high concentration.The protection member 167 may comprise a portion of the same conductiveimpurity as the ohmic contacts 163 and 165. The ohmic contacts 163 and165 may be formed by plasma-treatment under phosphine. Furthermore, theprotection member 167 may comprise a silicon oxide or a silicon nitride,and may be formed by another plasma-treatment.

The ohmic contacts 163 and 165 and the protection member 167 aredisposed on the semiconductor 154, and the planar shape of the sum ofthe ohmic contacts 163 and 165 and the protection member 167 issubstantially the same as that of the semiconductor 154.

The ohmic contacts 163 and 165 include a first portion disposed underthe data line 171 and a second portion disposed under the drainelectrode 175, and they may reduce the contact resistance between thesemiconductor 154 and the data line 171 and/or the drain electrode 175.

The protection member 167 is disposed between the first portion and thesecond portion of the ohmic contacts 163 and 165. The protection member167 is at the same layer as the ohmic contacts 163 and 165 and iscontinuous with them. Furthermore, the protection member 167 is notcovered by the data line 171 and the drain electrode 175.

The protection member 167 and ohmic contact 163 and 165 may be formed ofone semiconductor layer doped with an impurity at a high concentration.The protection member 167 may be manufactured by plasma-treating aportion of the impurity semiconductor layer, and the two portions of theimpurity semiconductor layer disposed at respective sides of theprotection member 167 may be divided from each other by the formation ofthe protection member 167 and form the first portion and the secondportion of the ohmic contacts 163 and 165, respectively.

The protection member 167 connected between the first portion and thesecond portion of the ohmic contacts 163 and 165 may have asubstantially continuous surface with the ohmic contacts 163 and 165.

The protection member 167 may be expanded in a depth direction to thegate electrode 124 consuming a portion of top surface of thesemiconductor 154.

The data line 171 and drain electrode 175 may have almost the sameplanar shape as the ohmic contacts 163 and 165 and almost the sameplanar shape as the semiconductor 154 except for a portion between thesource electrode 173 and the drain electrode 175. However, they may nothave the same planar shape in other embodiments.

One gate electrode 124, one source electrode 173, and one drainelectrode 175 form a thin film transistor (TFT) along with thesemiconductor 154, and a channel of a thin film transistor is formed atthe semiconductor 154 between the source electrode 173 and drainelectrode 175.

A color filter 230 having an opening 235 is formed on the data line 171,the drain electrode 175, the gate insulating layer 140, and theprotection member 167. The color filter 230 may comprise an organicmaterial, and it may display one of the primary colors such as a colorfrom three primary colors of red, green, and blue.

A capping layer 180 is formed on the color filter 230. The capping layer180 may comprise an inorganic insulator such as a silicon nitride(SiN_(x)) or a silicon oxide (SiO_(x)), or an organic insulator. Thecapping layer 180 may prevent dispersion of the color filter 230 andsuppress contamination of the liquid crystal by an organic material suchas a solvent of the color filter such that the deterioration such as theimage sticking that may be generated under screen driving may beprevented. The capping layer 180 has a contact hole 185 exposing thedrain electrode 175.

The pixel electrode 191 is formed on the capping layer 180. The pixelelectrode 191 is connected to the drain electrode 175 through thecontact hole 185 and the opening 235, and receives data voltages fromthe drain electrode 175. The pixel electrode 191 may comprise atransparent conductive material such as ITO or IZO.

Next, a manufacturing method of the display panel having the structureof the embodiments illustrated in FIG. 1 and FIG. 2 will be describedwith reference to FIG. 3 to FIG. 8 as well as FIG. 1 and FIG. 2,according to one or more embodiments.

FIG. 3 to FIG. 8 are cross-sectional views sequentially showing amanufacturing process of a display panel according to one or moreembodiments.

First, as shown in FIG. 3, a gate line 121 including a gate electrode124 is formed on a substrate 110. Next, a gate insulating layer 140 thatmay comprise a silicon nitride, an intrinsic semiconductor layer 150,and an extrinsic semiconductor layer 160 may be sequentially formed byplasma enhanced chemical vapor deposition (PECVD).

The intrinsic semiconductor layer 150 may comprise hydrogenatedamorphous silicon, and the extrinsic semiconductor layer 160 maycomprise n+hydrogenated amorphous silicon into which an n-type impuritysuch as phosphorus (P) is doped at a high concentration. However, asilicide layer may be formed as a substitute for the extrinsic amorphoussilicon layer 160.

The thickness of the intrinsic semiconductor layer 150 may be in a rangefrom about 100 Å to about 2000 Å, and the thickness of the extrinsicsemiconductor layer 160 may be in a range from about 100 Å to about 500Å.

In addition, according to an embodiment in which the intrinsicsemiconductor layer 150 comprises amorphous silicon, polysilicon may beformed through crystallizing the amorphous silicon using devices such asa laser generator. Polysilicon with high crystallinity may be formedthrough low energy when the laser is a high frequency and longwavelength laser such as a diode pumped solid state (DPSS) laser.Lateral crystallization may occur by moving a laser in parallel with theintrinsic semiconductor layer 150, and, in this case, uniformity of thesemiconductor surface improves. On the other hand, a micro-crystalsilicon instead of an amorphous silicon may be used. The intrinsicsemiconductor layer 150 may be a hybrid layer comprising a micro-crystalsilicon layer and an amorphous silicon layer.

The thickness of the intrinsic semiconductor layer 150 may be in a rangefrom about 100 Å to about 1000 Å. Due to a thinner intrinsicsemiconductor layer, response characteristics of a thin film transistormay improve.

The extrinsic semiconductor layer 160 may be formed by plasma-treatmentunder phosphine. According to an embodiment in which the surface of theintrinsic semiconductor layer 150 comprising polysilicon is treated byplasma under phosphine, the extrinsic semiconductor layer 160 comprisinga doped polysilicon on the intrinsic semiconductor layer 150 is formed.The output of radio frequency (RF) is in a range from about 600 W toabout 1,400 W, and the time of processing the plasma-treatment may be 90seconds or less.

The thickness of the extrinsic semiconductor layer 160 may be in a rangefrom about 10 Å to about 100 Å. Due to a thinner extrinsic semiconductorlayer 160, characteristics of the interface between dopants andpolysilicon may be maintained. Also, the protection member 167 may beeliminated by a simple cleaning process using a material such ashydrogen fluoride instead of a dry etching process which is a time andcost consuming process. The time of processing a dry etch may be about 5minutes. FIG. 16 and FIG. 17 are Time of Flight Secondary Ion MassSpectrometry (TOF-SIMS) graphs according to one or more embodiments.FIG. 16 shows a before-HF-cleaning structure, and FIG. 17 shows anafter-HF-cleaning structure. As compared FIG. 16 with FIG. 17, aconcentration of phosphorous atom is reduced, which means the protectionmember 167 may be eliminated through the HF-cleaning process.Consequently, a leakage current of the thin film transistor caused byresidual conducting elements such as phosphorous atoms in the protectionmember 167 not reacting with incorporated oxygen atoms through aplasma-treatment may be reduced.

The intrinsic semiconductor layer 150 comprising polysilicon may becleaned by materials such as hydrogen fluoride. This cleaning may beperformed before forming the extrinsic semiconductor layer 160, andunnecessary by-products on the surface of the intrinsic semiconductorlayer 150 are eliminated by the cleaning. As a result, reactivitybetween polysilicon and phosphorous (P) improves in this case whenforming the extrinsic semiconductor layer 160. Further, the extrinsicsemiconductor layer 160 is not etched by the cleaning because thecleaning is performed before forming the extrinsic semiconductor layer160.

Next, a conductor layer 170 comprising a chemically resistant metal suchas molybdenum, chromium, tantalum, copper, or titanium is deposited bysputtering on the extrinsic semiconductor layer 160. Next, aphotosensitive film 50 is coated through spin coating on the conductorlayer 170.

As shown in FIG. 4, the photosensitive film 50 is then exposed anddeveloped to form a photosensitive member 51. The photosensitive member51 includes a first portion 51A and a second portion 51B that is thinnerthan the first portion 51A. For convenience of explanation, but withoutlimiting the scope of the present embodiment, a first portion denotesportions of the conductor layer 170, the extrinsic semiconductor layer160, and the intrinsic semiconductor layer 150 that are disposed underthe first portion 51A of the photosensitive member 51, a second portiondenotes portions thereof disposed under the second portion 51B, and athird portion denotes portions thereof disposed under remainingportions.

Next, the third portion of the conductor layer 170 that is not coveredby the photosensitive member 51, and is exposed, may be removed by wetetching to form a data conductor 174. Alternatively, the data conductor174 may be formed by dry etching.

As shown in FIG. 5, the third portions of the extrinsic semiconductorlayer 160 and the intrinsic semiconductor layer 150 may be dry-etched toform an intrinsic semiconductor 154 and an extrinsic semiconductor 164.

Next, as shown in FIG. 6, the second portion 51B of the photosensitivemember 51 is removed and the thickness of the first portion 51A isreduced. In the embodiment of FIG. 6, reference numeral 52 indicates thefirst portion 51A of the photosensitive member 51 of which the thicknessis reduced, and this portion may again be used as a photosensitivemember. The second portion of the data conductor 174 that is not coveredby the photosensitive member 52, and is exposed, may then be dry-etchedto divide a data line 171 to include a source electrode 173 and a drainelectrode 175 that are discontinuous from each other. Thus, the secondportion of the extrinsic semiconductor 164 is exposed.

Next, as shown in FIG. 7, the second portion of the extrinsicsemiconductor 164 may be treated by plasma to form a protection member167 that may comprise a silicon oxide. The protection member 167 mayalternatively comprise a nitride material. Accordingly, the extrinsicsemiconductor 164 is divided into the protection member 167 and theohmic contacts 163 and 165 disposed on respective sides of theprotection member 167. Here, the plasma treatment may be applied to theintrinsic semiconductor 154 such that the protection member 167 may beformed inside the intrinsic semiconductor 154. All available devicesthat may generate the plasma such as a chemical vapor depositionapparatus and/or an etch apparatus may be used for the plasma treatment.For example, PE (plasma etching), RIE (reactive ion etching), ECCP(enhanced capacitive coupled plasma), DFCCP (dual frequency capacitivecoupled plasma), or ICP (inductively coupled plasma) may be used. Thegas for the plasma treatment may be almost all oxygen gas (O₂), and inaddition, argon (Ar) or helium (He) may be added.

When executing the plasma treatment, radio frequency (RF) power,pressure, kind of gas, amount of gas, process time, etc., may bevariously designed according to the apparatus used and the thickness ofthe extrinsic semiconductor 164. That is, the process conditions of theapparatus may be controlled to plasma-treat the entire thickness of theextrinsic semiconductor 164.

For example, when a dry etch apparatus is used, the process conditionsinclude RF power of 1300 W(source)/400 W(bias), pressure of 50 mTorr,oxygen gas (O₂) and argon (Ar) with amounts of gas (O₂/Ar) of 400/100sccm, and process time of 60 seconds. As a result, a protection memberhaving a thickness of 342 Å may be obtained. The protection member 167was formed on the exposed second portion of the extrinsic semiconductor164 with a thickness of about 100 Å by using the dry etching apparatusincluding the RIE/ECCP having strong anisotropy, and thencharacteristics of the thin film transistor were measured.

FIG. 14 is a graph showing the operation result of the thin filmtransistor after forming the protection member 167 according to anembodiment with the process conditions of the RF power of 1300W(source)/400 W(bias), the pressure of 15 mTorr, the use of oxygen gas(O₂) with an amount of gas of 100 sccm, and the process time of 5minutes. FIG. 15 is a graph showing the operation result of the thinfilm transistor after forming the protection member 167 according toanother embodiment with the process conditions of the RF power of 1300W(source)/400 W(bias), the pressure of 15 mTorr, the use of the oxygengas (O₂) and argon (Ar) with an amount of gas of 50/200 sccm (O₂/Ar),and the process time of 5 minutes. As shown in FIG. 14 and FIG. 15, whenan “off” voltage was −7V, the drain current was determined to be in arange from about 10⁻¹⁰ A to about 10⁻¹¹ A, and when an “on” voltage was20V, the drain current was determined to be in a range from about 10⁻⁵ Ato about 10⁻⁶ A. Therefore, it was confirmed that the thin filmtransistors operated normally.

Accordingly, the intrinsic semiconductor layer 150 may be deposited withthe original necessary thickness plus an additional thickness. In moredetail, when the exposed second portion of the extrinsic semiconductor164 is removed to expose the intrinsic semiconductor 154, the etchprocess is sufficiently executed to completely remove remnants of theextrinsic semiconductor 164 such that the portion of the intrinsicsemiconductor 154 may be etched. Accordingly, when depositing theintrinsic amorphous silicon layer 150, the intrinsic semiconductor layer150 may be deposited with a greater thickness than the necessaryresultant thickness (for example 100 Å to 2000 Å). However, in thepresent exemplary embodiment, when the second portion of the extrinsicsemiconductor 164 is completely oxidized in the process of the plasmatreatment, because the intrinsic semiconductor 154 is slightly oxidized,the intrinsic semiconductor layer 150 may be deposited with thenecessary resultant thickness (for example, 100 Å to 2000 Å) that isrequired to form the channel of the thin film transistor.

This plasma treatment process may be executed under the condition inwhich the photosensitive member 52 remains under the source electrode173 and the drain electrode 175. However, the plasma treatment processmay be executed under the condition in which the photosensitive member52 is removed through an ashing process. In this case, the sourceelectrode 173 and the drain electrode 175 may be oxidized, but if thecondition of the plasma treatment is controlled, damage to the sourceelectrode 173 and the drain electrode 175 may be prevented. Also, whenthe source electrode 173 and the drain electrode 175 are formed of ametal having a low affinity to oxidization such as copper, theoxidization thereof may be ignored.

In addition, the process for the plasma treatment may be executed in thesame chamber along with the etch process for the formation of theintrinsic semiconductor 154 and the extrinsic semiconductor 164, theashing process for the formation of the photosensitive member 52, andthe etch process for the formation of the source electrode 173 and thedrain electrode 175. Furthermore, the conductor layer 170 may bedry-etched to form the data conductor 174, and this process may beexecuted in the same chamber. Accordingly, all processes may be speedilyand simply executed in one chamber, from depositing the conductor layer170 until the plasma treatment.

Next, as shown in FIG. 8, the color filter 230 having the opening 235may be formed. When the protection member 167 does not exist, since thecolor filter 230 comprises an organic material, the intrinsicsemiconductor 154 that contacts the color filter 230 may be damagedduring the formation of the color filter 230. It will be appreciatedthat this danger is not generated in the present exemplary embodiment.Also, the function of the semiconductor 154 is not deteriorated by thecolor filter 230 after forming the color filter 230.

Next, a capping layer 180 comprising an inorganic insulator is formedand patterned by photolithography to form a contact hole 185 exposingthe drain electrode 175.

The thickness of the capping layer 180 may be in a range from about 100Å to about 2000 Å. When the thickness of the capping layer 180 is lessthan about 100 Å, it may be difficult for the thickness of the cappinglayer 180 to be uniform, and when the thickness thereof is more thanabout 2000 Å, the protection effect according to the increased thicknessmay not increase.

Next, a transparent conductive material such as ITO or IZO may bedeposited by sputtering on the capping layer 180 and patterned to form apixel electrode 191.

Thus, the process for etching the extrinsic semiconductor 164 to exposethe channel of the intrinsic semiconductor 154 and the process forforming the inorganic insulating layer to protect the channel of theintrinsic semiconductor 154 may be omitted. Accordingly, themanufacturing process of the display panel 10 may be simplified, andfurthermore a reduction of manufacturing cost and an improvement inproductivity may be obtained.

Also, by executing the plasma treatment, it is not necessary for thedisplay panel to be soaked in an electrolyte solution of a high pricesuch as in an anodic oxidation process, such that the process may besimplified and the cost may be reduced. Furthermore, when the displaypanel is soaked in the electrolyte solution for the anodic oxidationprocess, particles may cover the oxidized portion, however, thisdeterioration may be prevented by using the plasma treatment.

An additional photolithography is also required for the anodic oxidationprocess, and furthermore the display panel is soaked in the electrolytesolution such that an apparatus including a solution instrument that islarger than the display panel is required. In addition, the number ofdisplay panels for which the anodic oxidation process may be executed byusing the electrolyte solution of one solution instrument is restrictedto less than about 200 sheets. However, the plasma treatment may beexecuted to form the protection member in the present exemplaryembodiment such that the photolithography process and the apparatusincluding the solution having the electrolyte solution may not benecessary, and it may not be necessary for the electrolyte solution tobe changed every 200 sheets. Accordingly, the manufacturing process maybe speedily and simply executed and the manufacturing cost may bereduced.

On the other hand, when the capping layer 180 is formed of the organiclayer without the application of the color filter 230, the protectionmember 167 also has the same functions.

Next, a display device according to another exemplary embodiment of thepresent invention will be described in detail with reference to FIG. 9to FIG. 12. The present exemplary embodiment is described using a liquidcrystal display, however, it will be understood that embodiments of thepresent invention may be adapted to various kinds of display devices,and the range of the embodiments of the present invention is notrestricted to the liquid crystal display.

FIG. 9 is a layout view of a display device according to anotherexemplary embodiment of the present invention, FIG. 10 is a layout viewof the thin film transistor array panel shown in FIG. 9, FIG. 11 is alayout view of the common electrode panel shown in FIG. 9, FIG. 12 is across-sectional view of the display device shown in FIG. 9 taken alongthe line XII-XII, and FIG. 13 is a cross-sectional view of the displaydevice shown in FIG. 9 taken along the line XIII-XIII.

Referring to FIG. 9, FIG. 10, FIG. 12, and FIG. 13, a liquid crystaldisplay 20 includes a thin film transistor array panel 100, a commonelectrode panel 200, and a liquid crystal layer 3.

First, the thin film transistor array panel 100 will be describedaccording to one or more embodiments. The structure of the thin filmtransistor array panel 100 is almost the same as that of the exemplaryembodiment shown in FIG. 1 and FIG. 2.

A plurality of gate lines 121 and a plurality of storage electrode lines131 are formed on an insulating substrate 110.

The gate lines 121 extend substantially in a transverse direction andtransmit gate signals. Each gate line 121 includes a plurality of gateelectrodes 124 and an end portion 129 having a large area for connectionwith another layer or an external driving circuit.

The storage electrode lines 131 are supplied with a predeterminedvoltage such as a common voltage, and include a plurality of stem linesparallel to the gate lines 121 and a plurality of storage electrodes 133a, 133 b, 133 c, and 133 d, and a plurality of connections 133 e.

A gate insulating layer 140 is formed on the gate lines 121 and thestorage electrode lines 131. A plurality of semiconductor stripes 154that may comprise hydrogenated amorphous silicon or polysilicon areformed on the gate insulating layer 140.

A plurality of ohmic contacts 163 and 165 and a plurality of protectionmembers 167 are formed on the semiconductors 154.

A plurality of data lines 171, a plurality of drain electrodes 175, anda plurality of isolated metal pieces 178 are formed on the ohmiccontacts 163 and 165, and on the gate insulating layer 140.

The data lines 171 transfer data signals and basically extend in avertical direction, thereby crossing the gate lines 121 and the stemlines and connections 133 e of the storage electrode lines 131. Eachdata line 171 includes a plurality of source electrodes 173 extendingtoward the gate electrodes 124, and a wide end 179 for connection toanother layer or an external driving circuit. The drain electrodes 175are separated from the data lines 171 and face the source electrodes 173with respect to the gate electrodes 124. The isolated metal pieces 178are disposed on the gate lines 121 neighboring the first storageelectrodes 133 a.

The semiconductors 154 extend in a vertical direction and include aplurality of protrusions extending toward the gate electrodes 124 andthe drain electrodes 175. The semiconductors 154 include portions thatare exposed without being covered by the data lines 171 and the drainelectrode 175 as well as between the source electrode 173 and the drainelectrode 175.

The ohmic contacts 163 and 165 may comprise amorphous silicon doped withan impurity at a high concentration or polysilicon. The ohmic contacts163 and 165 may be formed by plasma-treatment under phosphine. Theprotection member 167 may comprise a silicon oxide or a silicon nitride.The protection member 167 may also be formed by anotherplasma-treatment.

The ohmic contacts 163 and 165 include first portions disposed betweenthe semiconductors 154 and the data lines 171 and second portionsdisposed between the semiconductors 154 and the drain electrodes 175,thereby reducing the contact resistance between the semiconductors 154and the data lines 171 and/or drain electrodes 175.

A plurality of protection members 167 are formed between the firstportions and the second portions of ohmic contacts 163 and 165. Theprotection members 167 are disposed at the same layer as the ohmiccontacts 163 and 165 and are continuous with them, and are not coveredby the data lines 171 and drain electrodes 175.

The protection members 167 and the ohmic contacts 163 and 165 may beformed of one semiconductor layer that is doped with an impurity at ahigh concentration. The protection members 167 may be made byplasma-treating a portion of the extrinsic semiconductor layer, andportions of the extrinsic semiconductor layer disposed on both sides ofthe protection member 167 are divided by forming the protection member167 such that the first portions and the second portions of ohmiccontacts 163 and 165 are formed. The protection member 167 may comprisea silicon oxide or a silicon nitride.

A plurality of color filters 230 having a plurality of openings 235 areformed on the data lines 171, the drain electrodes 175, the gateinsulating layer 140, the isolated metal pieces 178, and the protectionmembers 167. The color filters 230 may comprise an organic material, andmay display one of the primary colors such as one of three primarycolors of red, green, and blue.

A capping layer 180 is formed on the color filters 230. The cappinglayer 180 has a plurality of contact holes 182 and 185 respectivelyexposing the end portions 129 and 179 of the data lines 171 and thedrain electrodes 175. The capping layer 180 and the gate insulatinglayer 140 have a plurality of contact holes 181, 184 a, and 184 brespectively exposing the end portions 129 of the gate lines 121 and theportions of the storage electrode lines 131.

A plurality of pixel electrodes 191, a plurality of contact assistants81 and 82, and a plurality of connecting bridges 84 are formed on thecapping layer 180. They may comprise a transparent conductor such as ITOor IZO, or a reflective conductor such as aluminum, silver, or alloysthereof. The pixel electrodes 191 are connected to the drain electrodes175 through the contact holes 185.

The pixel electrodes 191 overlap the storage electrode lines 131 as wellas the storage electrodes 133 a, 133 b, 133 c, and 133 d. A plurality ofcutouts 91, 92 a, and 92 b are formed in the pixel electrodes 191, andthe pixel electrodes 191 are divided into a plurality of regions by thecutouts 91, 92 a, and 92 b. The number of cutouts may be varieddepending on design factors such as the size of pixels, the ratio of thetransverse edges and the longitudinal edges of the pixel electrodes, thetype and characteristics of the liquid crystal layer 3, and so on.

The contact assistants 81 and 82 are connected to the end portions 129of the gate lines 121 and the end portions 179 of the data lines 171through the contact holes 181 and 182, respectively. The contactassistants 81 and 82 protect the end portions 129 and 179 and complementthe adhesion of the end portions 129 and 179 and external devices.

The connection bridges 84 intersect the gate lines 121, and areconnected to the exposed portions of the storage electrodes 131 throughthe contact holes 184 a and 184 b that are opposite to each other withthe gate lines 121 therebetween. The storage electrode lines 131 and theconnecting bridges 84 may be used for repairing defects of the gatelines 121, the data lines 171, or the thin film transistors.

In the present exemplary embodiment, the order of forming thesemiconductors 154, the ohmic contacts 163 and 165, the sourceelectrodes 173, and the drain electrodes 175 is different from the ordershown in the embodiments of FIG. 3 to FIG. 8.

First, an intrinsic amorphous silicon layer and an extrinsic amorphoussilicon layer are formed on a gate insulating layer 140, and theintrinsic amorphous silicon layer and the extrinsic amorphous siliconlayer may be dry-etched by using a mask to form a plurality ofsemiconductors 154 and a plurality of extrinsic semiconductors. Next, aconductor layer may be formed by sputtering on the gate insulating layer140 and the extrinsic semiconductor, and patterned by wet-etching ordry-etching to divide into the source electrodes 173 the drainelectrodes 175. Here, the portions of the extrinsic semiconductors areexposed between the source electrodes 173 and the drain electrodes 175.Next, the exposed extrinsic semiconductors are plasma-treated to form aplurality of protection members 167. Accordingly, the extrinsicsemiconductors are divided into the protection member 167 and the ohmiccontacts 163 and 165 that are disposed on respective sides thereof.Here, the plasma treatment may be applied through to the semiconductor154 such that the protection member 167 may be formed on thesemiconductor 154.

Next, the common electrode panel 200 will be described in detailaccording to one or more embodiments with reference to FIG. 9, FIG. 11,and FIG. 12.

A light blocking member 220 is formed on a substrate 210. The lightblocking member 220 includes a plurality of openings 225 that face thepixel electrodes 191 and have substantially the same shape as the pixelelectrodes 191, thereby preventing light leakage between the pixelelectrodes 191. An insulating layer 250 is formed on the light blockingmember 220 for providing a flat surface. The insulating layer 250 may beomitted.

A common electrode 270 that may comprise a transparent conductor such asITO or IZO is formed on the insulating layer 250. The common electrode270 includes a plurality of sets of cutouts 71, 72 a, and 72 b. Theshape of the cutouts 71, 72 a, and 72 b may be changed according todesign elements.

The liquid crystal layer 3 is disposed between the thin film transistorarray panel 100 and the common electrode panel 200.

The liquid crystal display 20 may include a backlight unit (not shown)for supplying light to the thin film transistor array panel 100, thecommon electrode panel 200, and the liquid crystal layer 3.

According to an exemplary embodiment of the present invention, theextrinsic semiconductor may be plasma-treated such that the process foretching the extrinsic semiconductor and forming an inorganic insulatinglayer for protecting the intrinsic semiconductor may be omitted.Accordingly, the manufacturing process of the display panel may besimplified, the manufacturing cost may be reduced and productivity maybe improved.

Also, according to an exemplary embodiment of the present invention, theprocess for the plasma treatment may be executed in the same chamberalong with the etch process for the formation of the extrinsicsemiconductor, the ashing process for the formation of thephotosensitive member, and the etch process for the formation of thesource electrode and the drain electrode, such that the manufacturingprocess may be speedily and simply executed.

According to an exemplary embodiment of the present invention, it is notnecessary for the display panel to be soaked in an electrolyte solutionof a high price such as in an anodic oxidation process, so that theprocess may be simplified and the cost may be reduced. Also, when thedisplay panel is soaked in the electrolyte solution for the anodicoxidation process, particles may cover the oxidized portion, however,this deterioration may be prevented by using the plasma treatment.

According to an exemplary embodiment of the present invention, becausethe thin doped polysilicon layer is formed by plasma-treatment of thethin polysilicon layer under phosphine, characteristics of the interfacebetween dopants and polysilicon are maintained and the time of formingthe protective member is reduced, thereby improving the responsecharacteristics of a thin film transistor and productivity.

While practical exemplary embodiments have been described, it is to beunderstood that the disclosure is not limited to the disclosedembodiments, but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

1. A manufacturing method of a display panel, comprising: forming a gateline including a gate electrode on a substrate; forming a gateinsulating layer on the gate electrode; forming an intrinsicsemiconductor on the gate insulating layer; forming an extrinsicsemiconductor on the intrinsic semiconductor; forming a data lineincluding a source electrode and a drain electrode on the extrinsicsemiconductor; and plasma-treating a portion of the extrinsicsemiconductor between the source electrode and the drain electrode, theportion comprising a protection member and respective sides of theprotection member comprising ohmic contacts.
 2. The manufacturing methodof claim 1, further comprising forming an organic layer on theprotection member.
 3. The manufacturing method of claim 2, wherein theorganic layer is a color filter.
 4. The manufacturing method of claim 3,further comprising forming a pixel electrode connected to the drainelectrode on the organic layer.
 5. The manufacturing method of claim 1,wherein the intrinsic semiconductor comprises polysilicon and theextrinsic semiconductor comprises polysilicon.
 6. The manufacturingmethod of claim 5, wherein the forming of the extrinsic semiconductorcomprises plasma-treatment of the surface of the intrinsic semiconductorunder phosphine.
 7. The manufacturing method of claim 6, furthercomprising cleaning the intrinsic semiconductor after forming theintrinsic semiconductor before forming the extrinsic conductor.
 8. Themanufacturing method of claim 7, wherein the cleaning of the intrinsicsemiconductor uses hydrogen fluoride.
 9. The manufacturing method ofclaim 6, wherein the thickness of the extrinsic semiconductor is in arange from about 10 Å to about 100 Å.
 10. The manufacturing method ofclaim 1, wherein the protecting member comprises a portion of the sameconductive impurity as the ohmic contacts.
 11. A manufacturing method ofa display panel comprising: forming a gate electrode on a substrate;forming a gate insulating layer on the gate electrode; sequentiallydepositing a first material layer, a second material layer, and a thirdmaterial layer on the gate insulating layer; etching the third materiallayer, the second material layer, and the first material layer to form adata conductor, an extrinsic semiconductor, and an intrinsicsemiconductor; etching the data conductor to form a source electrode anda drain electrode and simultaneously exposing a first portion of theextrinsic semiconductor; plasma-treating the first portion of theextrinsic semiconductor between the source electrode and the drainelectrode, the first portion comprising a protection member andrespective sides of the protection member comprising ohmic contacts;forming a color filter on the source electrode, the drain electrode, andthe protection member; and forming a pixel electrode connected to thedrain electrode on the color filter.
 12. The manufacturing method ofclaim 11, further comprising forming a capping layer of an inorganicinsulator on the color filter.
 13. The manufacturing method of claim 11,wherein the plasma-treatment is executed by using a plasma generationapparatus including oxygen injected into a chamber.
 14. Themanufacturing method of claim 13, wherein argon (Ar) gas or helium (He)is additionally injected into the chamber.
 15. The manufacturing methodof claim 14, wherein the sequential etching of the third material layer,the second material layer, and the first material layer, the etching ofthe data conductor, and the plasma-treatment of the extrinsicsemiconductor are sequentially executed in the same plasma generationapparatus.
 16. The manufacturing method of claim 15, wherein the formingof the source electrode and the drain electrode includes forming aphotosensitive member on the third material layer, and removing anexposed portion of the data conductor by using the photosensitive memberas a mask, wherein the plasma-treating of the first portion of theextrinsic semiconductor is executed under a condition in which thephotosensitive member remains on the source electrode and the drainelectrode. 17.-25. (canceled)